Spark plug



Nov. -3 1925. 1,560,511

' .1... HIRSCH SPARK PLUG Filed July 2 1924 WITNESSES.

11v VENTOR,

Louis Jfirachw L ATTORNEYS.

' plug Patented Nov. 3, 1925.

PATENT OFFICE.

LOUIS HIRSCH, F MESILLA PARK, NEW MEXICO.

SPARK PLUG.

Application filed July 26, 1924. Serial No. 728,410.

To aZZ whom it may concern:

Be it known that I, LOUIS Hmson, a citizen of the United States, and a resident of Mesilla Park, in the county of Dona Ana and State of New Mexico, have invented a new and Improved Spark Plug, of which the following is a full, clear, and exact description.

This invention relates to improvements in spark plugs, an object of the invention being to provide a spark plug in which the core is rendered transparent or provided with a transparent portion which renders the spark visible from the outside of the A further object is to provide a spark .plug in which the core thereof is provided with an electrode and with a transparent plug in line with the terminal of the electrode and the terminal of the casing, spaced therefrom so that a spark gap is provided in line with the transparent plug.

Vith these and other objects in View, the invention consists in certain novel features of construction and combinations and arrangements of parts which will be more fully hereinafter described and pointed out in the claim.

In the accompanying drawings Figure 1 is a view in longitudinal section illustrating my improved spark plug;

Figure 2 is a view in transverse section on the line 2-2 of Figure 1.

1 represents the casing or jacket of my improved plug, which is externally screwthreaded at its inner end, as shown at 2, to screw into the cylinder of an engine. This using 1 is internally screw-threaded at its upper end, as shown at 3, for the reception of a nut 4 to clamp a core 5 in the casing. The casing 1 is made with an internal shoulder 6 and the core 5 is made with an external enlargement 7 so that a packing ring or gasket 8 may be located between the enlargement 7 and the shoulder 6, and a second gasket 9 may be located between the nut e and the enlargement 7 to render the plug gas-tight. This core 5 is of porcelain or other suitable insulating material and is formed with two longitudinal openings or bores 10 and 11, respectively, the latter be ing appreciably larger in diameter than the former. An electrode 12 is located in the bore 11 and has a binding post 13 at its outer end. A terminal 14 is formed on the inner end of the electrode 12 and spaced from a terminal 15 fixed to the casing 1 and grounded therethrough. These terminals 1-1 and 15 are spaced apart to form a spark gap which is located in alinement with the bore 11, and in this bore 11 a plug 16 of glass or any other suitable material is secured in any approved manner. In other words, the plug 16 may be baked in the enamel or it may be secured therein in any other way which will permit it to perform properly its functions of withstanding the temperatures of the engine and permitting a vision of the spark.

lVhile I refer to the material of the plug 16 as being porcelain, it is to be understood that I use this term in its broadest possible sense to include any. transparent or translucent material which will permit an observer to note whether or not the plug is sparking properly by observing the same through said material.

Various slight changes and alterations might be made in the general form of the parts described without departing from my invention, and hence I do not limit myself to the precise details set forth but consider myself at liberty to make such slight changes and alterations as fairly fall within the spirit and scope of the appended claim.

I claim:

A spark plug, comprising a casing, an insulating core in the casing having a pair of parallel bores extending throughout the length thereof, one bore being appreciably larger than the other, an electrode located in the smaller bore and projecting through the core, terminals on the electrode and on the inner end of the casing, spaced apart and providing an arc in line with the larger bore, and a transparent core extending throughout the length of the firstmentioned core and fitting the larger bore of the latter.

LOUIS HIRSCH. 

